How much were the coins worth?

Metals

Coinages in the Roman world were in gold, silver, and bronze. All issues of gold were imperial except for that coined in the client kingdom of Bosporus. A small number of cities produced silver issues, but the bulk of their coinage was the bronze which provided the greater part of the small change available in the East. ‘Provincial’ issues comprised silver coins, mostly drachms, didrachms, or tetradrachms, and accompanying bronze issues.
The gold in the kingdom of Bosporus and the civic and ‘provincial’ silver coinages were debased to various extents. We hope to publish analyses in the conventional publication. The term ‘bronze’ is used here to embrace leaded bronze, copper, and brass (orichalcum). For the most part analyses are not available to allow the alloy of base metal coinages to be specified, but analyses for an earlier period do not suggest that the precise metal is of any great denominational significance.

Denominations

Most provincial coins lack marks of value. People in the ancient world — as well as modern scholars trying to reconstruct provincial denominational systems — have had to rely on the metal, size, and weight of a coin and the image it bears in order to determine its face value. Presumably this was well-known when the coin was issued, but we have avoided assigning conjectural values to the coins in the website.

Among the cities which did place value marks on their coins, the case of Chios is of particular interest. Probably during the reign of Augustus, the city appears to have shifted from a traditional Greek denominational system based on obols to a ‘Romanized’ one based on the assarion, the Greek translation of the Latin as. Similar changes are likely to have occurred elsewhere, as demonstrated by Aegium — the other city that put marks of value on its Antonine coins. However, the use of OBO (presumably meaning obol) on the coins of Seleucia Pieria in Syria during the reign of Severus Alexander (AD 222–35) implies that traditional Greek denominational systems could survive well into the third century. In many cases we cannot even be sure whether the face value of a coin was expressed in Greek or Roman terms.